Edge-lit light fixture having capabilities for a secondary service

ABSTRACT

A light fixture is disclosed, and includes a light emitting diode (LED) engine including plurality of LEDs that transmit visible light. The light fixture also includes a waveguide, where the LEDs of the LED engine surround the waveguide and transmit the visible light in a direction towards the waveguide. The light fixture also includes a second element that provides a secondary service. The light fixture also includes a housing that defines a cavity, where the LED engine and waveguide are positioned within the cavity proximate the front of the light fixture, and the a secondary element is positioned within the cavity toward the rear of the light fixture.

TECHNICAL FIELD

The present disclosure relates generally to a light fixture, and moreparticularly to a light fixture that includes a light producing elementand at least one other element that provides a secondary service thatare both contained within a housing of the light fixture.

BACKGROUND

Light emitting diode (LED) based lighting systems may offer severalenergy and reliability advantages over other types of lighting systemssuch as, for example, incandescent or fluorescent lighting. Thus, LEDbased lighting systems are increasingly being used to replace otherexisting lighting technologies. Moreover, it should also be appreciatedthat LED based lighting systems also being used as components of othersystems such as home automation systems.

Automation systems are used to control various systems that aretypically found in homes and office buildings such as lights, heating,security systems, and home appliances. Some examples of appliances thatmay be controlled by an automation system include washers, dryers,ovens, and refrigerators. Some types of automation systems may alsointegrate various features and functions into a single device. In fact,sometimes light fixtures include a light producing element like a LEDlight engine as well as another element that provides another function.For example, the light fixture may include a speaker that produces soundor a microphone that detects a user's voice or other sounds.

Sometimes difficulties are encountered when attempting to packagemultiple components that each provide different functions into a singlelight fixture. This is because light fixtures are usually of a standardsize and shape, and therefore only have a limited amount of spaceavailable for accommodating various components. Furthermore, sometimesthe additional components may interfere with the light fixture's abilityto radiate light in a manner that is not only effective, but alsoaesthetically pleasing. There are also challenges with providing otherfunctions within the light fixture. For example, the sound quality orlevel of a speaker may be compromised in order to fulfill the lightfixture's lumen requirements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective, cross-sectioned view of the disclosed lightfixture;

FIG. 2 is an exploded view of the light fixture shown in FIG. 1;

FIG. 3 is an enlarged view of a portion of the light fixture of FIG. 1;and

FIG. 4 is another perspective view of the disclosed light fixture.

DETAILED DESCRIPTION

The following detailed description will illustrate the generalprinciples of the invention, examples of which are additionallyillustrated in the accompanying drawings. In the drawings, likereference numbers indicate identical or functionally similar elements.

FIG. 1 is a perspective, cross-sectioned view of an exemplary lightfixture 10. The light fixture 10 includes a bezel 20, a waveguide 22, asecondary element 26, a secondary element holder 28, a light emittingdiode (LED) engine 30, a first driver board 32, a driver board holder34, a second driver board 36, a housing 40, an end cap or cover 42, andone or more installation features 44 such as installation springs.Although the light fixture 10 shown in FIG. 1 illustrates a downlight,it is to be appreciated that the embodiment in FIG. 1 is merelyexemplary in nature. For example, in other embodiments the light fixture10 may be a parabolic aluminized reflector (PAR) type light fixture or abulged reflector (BR) type light fixture.

In addition to generating light, the light fixture 10 also includes thesecondary element 26, which is used to provide another, secondaryservice in addition to generating light. In the non-limiting embodimentas described, the secondary element 26 is a speaker for generatingsound. However, it is to be understood that the light fixture 10 is notlimited to a speaker. For example, in other embodiments the secondaryelement 26 may be a microphone or a motion detector.

The housing 40 defines a cavity 50 that is shaped to contain thesecondary element 26, the secondary element holder 28, the LED engine30, the first driver board 32, the driver board holder 34, and thesecond driver board 36. In the non-limiting embodiment as shown in FIG.1, the housing 40 includes a heat sink 46 that is constructed of aheat-conducting metal. The heat sink 46 coincides with an inner surface48 of the housing 40. In another embodiment, the housing 40 isconstructed of a material that is an electrical insulator that allowsfor radio frequency (RF) signals to pass through such as, but notlimited to, a thermally conductive plastic. The housing 40 defines afirst end portion 52 and a second end portion 54. The first end portion52 of the housing 40 defines a first opening 56 and the second endportion 54 defines a second opening 58 of the housing 40. As seen inFIG. 1, a portion 41 of the housing 40 may have a generallyfrustoconical profile, and the first opening 56 of the housing 40 islarger in size when compared to the second opening 58.

In the non-limiting embodiment as shown, the first end portion 52 of thehousing 40 is secured to the bezel 20, and the second end portion 54 ofthe housing 40 is secured to the cover 42. The bezel 20 may be securedto the first end portion 52 of the housing 40 by a snap-fit engagement.However, it is to be appreciated that the bezel 20 and the housing 40are not limited to a snap-fit engagement, and that other fasteningtechniques may be used as well to secure the bezel 20 to the housing 40.Furthermore, in an alternative embodiment, the bezel 20 and the housing40 may be integrated together into a single piece. The cover 42 may beused to close off or seal the second opening 58 of the housing 40.

FIG. 2 is an exploded view of the light fixture 10 shown in FIG. 1.Referring now to both FIGS. 1 and 2, the cover 42 may include one ormore locating features 60 for engaging and locating the second driverboard 36. The second driver board 36 may include various powerelectronics 62 required for electrical operation of the LED engine 30and the light fixture 10. The driver board holder 34 may include one ormore legs 70 that project in a direction towards the second end portion54 and cover 42 of the light fixture 10 when assembled. The legs 70 ofthe driver board holder 34 may act as locator pins or features that areused to engage and secure the driver board 36 in place within the cavity50 of the housing 40.

The driver board holder 34 may also define a ledge 72, where the ledge72 defines a recessed surface 74 (corresponding position exterior of theholder 34 is indicated in FIG. 2) that the first driver board 32 may beseated upon. The first driver board 32 may be a printed circuit board(PCB) and may include an antenna (not shown), such as a trace antenna.However, those skilled in the art will appreciate that the disclosureshould not be limited to a trace antenna and PCB. In one embodiment, theantenna may be configured to receive a short-range RF signal such as,for example, a Bluetooth® signal conforming to the Institute ofElectrical and Electronics Engineers (IEEE) Standard 802.15.Furthermore, in one embodiment, the antenna may be a multi-band antennathat operates at different RF frequency bands.

Referring to FIG. 1, the secondary element 26 includes a first endportion 76 and a second end portion 78. The first end portion 76 of thesecondary element 26, which is illustrated as a speaker, is seatedagainst a front face 80 of the driver board holder 34. Referring now toboth FIGS. 1 and 2, the secondary element holder 28 defines a first endportion 82, a second end portion 84, and a cavity 86 that extends in anaxial direction along a central axis A-A of the light fixture 10. Thefirst end portion 82 of the secondary element holder 28 includes one ormore retaining flanges 90. As seen in FIG. 1, the flanges 90 of thesecondary element holder 28 may engage the holder 28 to a retainingfeature 92 located along the inner surface 48 of the housing 40.

The second end portion 84 of the holder 28 defines a flange 96 thatextends in an inward direction with respect to the axis A-A of the lightfixture 10. As seen in FIG. 1, the flange 96 defines an opening 100 thatis smaller in size than the second end portion 78 of the secondaryelement 26. Thus, a rear face 98 of the flange 96 of the secondaryelement holder 28 retains the secondary element 26 in place within thehousing 40 of the light fixture 10. For example, in the embodiment asshown the light fixture 10 is a downlight. Therefore, when the downlightis installed in a building, the end cap 42 is positioned so as to be ontop or at the upper end of the light fixture 10. When the downlight isinstalled, the flange 96 of the secondary element holder 28 prevents thesecondary element 26 from migrating downwards and contacting thewaveguide 22.

The light fixture 10 is an edge-lit device. That is, the LED lightengine 30 surrounds the waveguide 22 in the plane of the waveguide,i.e., surrounds the lateral edges of the waveguide 22 with respect tothe central axis A-A of the light fixture. The waveguide 22 isconstructed of the material including properties that illuminate anentire face 102 (FIGS. 1 and 4) of the waveguide 22 using the lightgenerated by the LED engine 30. One advantage of using an edge-litdevice is cost reduction, since fewer LEDs are typically required toproduce the same lumen output. Referring to FIGS. 1 and 3, the LED lightengine 30 includes a backing material 104 and a plurality of LEDs 106that are mounted upon the backing material 104. The backing material 104may be a relatively flexible material. Specifically, the backingmaterial 104 may be formed as a strip, and the strip may be bent intothe annular or ring-shaped configuration as seen in FIG. 3. Thus, theLED light engine 30 may completely extend around a circumference 110(FIG. 2) of the waveguide 22. That is, in other words, the LEDs 106surround the waveguide 22, and transmit visible light in a directiontowards the waveguide 22.

Referring now to FIG. 4, the waveguide 22 may also be referred to as alens or a light guide. The waveguide 22 is used to collect the lightgenerated by the LEDs 106, and directs the light to the front face 102of the waveguide 22 to provide illumination. The waveguide 22 mayinclude a plurality of light deflecting elements (not illustrated),which are also referred to as microstructures or three-dimensionalelements. In one embodiment, the light deflecting elements are prismaticcavities formed in a longitudinal direction of the waveguide 22, and areused to illuminate the entire front face 102 of the waveguide 22. Thelight deflecting elements are distributed along the front face 102 ofthe waveguide 22.

The waveguide 22 may define a plurality of apertures 112, which aredistributed in a predefined pattern along the front face 102 of thewaveguide 22. In the embodiment as shown, the apertures 112 allow soundgenerated by the secondary element 26 (FIGS. 1 and 2), which isillustrated as a speaker, to be transmitted to the environment. Theapertures 112 may be arranged into a starburst pattern where theapertures 112 are arranged to radiate outwardly from a central pointalong the front face 102 of the waveguide 22. However, it is to beappreciated that the embodiment as shown in FIG. 4 is merely exemplaryin nature, and that the apertures 112 may be arranged into a variety ofother patterns and configurations as well.

It is to be appreciated that the apertures 112 are arranged so as toprovide acceptable sound quality, and to also provide light that is notonly aesthetically pleasing, but also meets any light output or lumenrequirements. In other words, the apertures 112 are arranged so as tocreate a light pattern that may be considered visually appealing to aconsumer.

Referring generally to the figures, the disclosed light assemblyprovides at least one other or secondary service to a consumer. Forexample, in the embodiments as shown, the secondary service is a speakerfor transmitting sound. The LED light engine is positioned around anddirects light towards the waveguide. The edge-lit LEDs require lesspackaging space when compared to conventional board-type LED lightengines, which are usually mounted along a central portion of a light.Therefore, the edge-lit LEDs allow for sufficient packaging space forthe elements associated with the secondary service. In other words, theedge-lit LED configuration results in increased packaging space toaccommodate the speaker. Furthermore, the sound quality or level of aspeaker is not compromised in order to fulfill the light fixture's lumenrequirements.

While the forms of apparatus and methods herein described constitutepreferred embodiments of this invention, it is to be understood that theinvention is not limited to these precise forms of apparatus andmethods, and the changes may be made therein without departing from thescope of the invention.

What is claimed is:
 1. A light fixture, comprising: a light emittingdiode (LED) engine including plurality of LEDs that transmit visiblelight; a waveguide, wherein the plurality of LEDs of the LED enginesurround the waveguide and transmit the visible light in a directiontowards the waveguide; a housing that defines a cavity, wherein the LEDengine and waveguide are positioned within the cavity within a first endportion of the housing comprising the front of the light fixture; and asecondary element that provides a secondary service, wherein thesecondary element is positioned within the cavity between the first endportion and a second end portion of the housing comprising the rear ofthe light fixture.
 2. The light fixture of claim 1, wherein thesecondary element includes a speaker.
 3. The light fixture of claim 1,wherein the secondary element includes a microphone.
 4. The lightfixture of claim 2, wherein the waveguide defines a plurality ofapertures that allow sound generated by the speaker to be transmitted tothe environment.
 5. The light fixture of claim 1, wherein the lightfixture is a downlight.
 6. The light fixture of claim 1, wherein theplurality of LEDs of the LED engine are mounted upon a backing material,and the backing material is shaped as an annular ring extending around acircumference of the waveguide.
 7. The light fixture of claim 1, whereinthe first end portion of the housing includes a heat sink, constructedof a heat-conducting metal, that coincides with an inner surface of thehousing.
 8. The light fixture of claim 1, wherein the light fixturefurther comprises: first and second driver boards positioned with thecavity between the second end portion and the secondary element; and adriver board holder interposed between the first and second driverboards and the secondary element, wherein the secondary element seatsagainst a front face of the driver board holder; and a secondary elementholder interposed between the secondary element and the waveguide. 9.The light fixture of claim 8, wherein the front face of the driver boardholder defines a ledge, and the ledge defines a recessed surface thatthe first driver board is seated upon.
 10. The light fixture of claim 9,wherein the first driver board includes an antenna configured to receivea short-range RF signal.
 11. The light fixture of claim 9, wherein thedriver board holder includes one or more legs that project in adirection towards the second end of the housing, and the one or morelegs engage the second driver board to secure the second driver boardwithin the cavity.
 12. The light fixture of claim 11, further comprisingan end cap secured to the second end portion of the housing, wherein theend cap includes a locator feature engaging the second driver board. 13.The light figure of claim 8, wherein the secondary element includes afirst end portion, and the first end portion includes one or moreretaining flanges that engage a retaining feature located along an innersurface of the housing.
 14. The light fixture of claim 13, wherein thesecondary element includes a second end portion, wherein the second endportion is positioned frontward of the first end portion and the secondend portion includes an inwardly extending flange that defines anopening that is smaller than the second end portion.
 15. The lightfixture of claim 14, wherein the secondary element is seated between thefront face of the driver board holder and a rear face of the inwardlyextending flange.